Method of making flat expanded grilles



I Oct. 22; 1935. 0, QTTE 2,018,085

METHOD OF MAKING FLAT EXPANDED- GRILLES Filed May 29, 1954 6 Sheets-Sht l INVENTOR a @zbmm gzwm m Oct. 22, '1935.

o. M. OTTE METHOD OF MAKING FLAT EXPANDED GRILLES Filed May '29, 1934 6 Sheets-Sheet 2 0a. 22, 1935. o. M. OTTE 8,

' METHOD'OF MAKING FLAT EXFANDED GRILLES Filed May 29, 1954 s Sheets-Sheet s lull lllll llllllmlllll "III "III Ifllll m lllll ll llillwlllll a R \R\M\ I v I O O s W O W 0 K 6 O O O 0 O I 6 ffmvmfm Oct. 22, 1935. o. M. OTTE 85 METHOD OF MAKING FLAT EXPANDED GRILLES Filed May 29, 1954 6 Sheets-Sheet 4 llilll lmlmmmu: lull:

:m 'iii' m ml INVENTOR m a m WWW 0a. 22, 1935. o M OTTE 2,018,685

METHOD OF MAKING FLAT EXPANDED GRILLES Filed May 29, 1954 6 Sheets-Sheet 5 RQQKM Nk Oct. 22, 1935. O M OTTE 2,018,085

' METHOD OF MAKING FLAT EXPANDED GRILLES Flled May 29, 1934 6 Sheets-Sheet 6 and in fact, for many use made from sheet I Patented Oct. 22,

was

A 'UNITED STATES PATENT orifice This invention relates IMETHOD OF MAKING FLAT EXPANDED ILLES Otho M. Otto,

gheny Steel Company, sylvanla Tar'enturn, Fa, assignor to Allea corporation of Benn- Application May 29, 1934, Serial No. 728,060

5 Claims. broadly to the art of metalworking and more especially to methods of making metal grilles. Grilles made from sheet metal are now used for coverings forradiators, coverings for ventilatori openings, coverings for doors and for windows Grilles steel sheet metal, from metal-such as stainless Monel metal and from stainless alloys of the group of which Allegheny metal ls an example, are erable extent.

In making now used to a considthe grilles from such sheet metal, the desired pattern or openwork the place of wire rod structure is .obtained by punching out the portions forming the interstices or voids, therefore, in order to make a grille of a certain size, a metal sheet of the same size is required and the punched out portions are scrap material.

Grilles, therefore, made in this manner are of necessity more or less expensive.

.I It has been proposed to utilize metal grilles or lattice structures for refrigerator shelving to take In making such grilles ing, it has been propose sheet-like material; to r shelving as now used.-

f or refrigerator shelvd to expand mild steel 011 the same flat after the expanding step is completed and then to form ,the same into a shelf structure; then to galvan-' he or has also been suggested otherwise plate such shelf structure.

It as desirable to utilize stainless steel or some other not easily corrodible metal to form such far as I am' aware,

expanded metalshelving. So no satisfactory way or method of making. such expanded grilles for refrigerator shelvin or the like has been devised.

Expanded grilles made from ordinary steel,

.when galvanized, tinned unsatisfactory for use in or otherwise coated, are

refrigerators because of their tendency to corrode.

An object of this method of invention is to provide a making relatively cheap openwork grilles or latticestructures from sheet metal of the type known as the groups stainless steel, from alloys of of which Allegheny metal is an exam- -ple and from metals such as Monel metal. Most of these metals are difilcult to work, because of the fact that they are work hardeningf; others are diflicult to work because of other characteristics.

in other words, that the It is necessary that grilles for such use be flat,

bars or strips bounding the interstices or voids of the grille all lie in the I same plane.

In making expanded metal by the now standard methods, the bars or strips bounding the inten such material, it

plane) is necessary as in "eningf alloys and use in carrying .out this Invention;

terstices lie in at least. two different planes angu larly disposedone to the other. In order to flatis necessary to press or roll down the upstanding portions, and when this is done with work hardening material, itis more 5 than likely to fracture crowd: at the points of bending.

An example of an expanded metal grille or lattice structure with the bars orstrips bounding the interstices or voids lying, in different an- 10 gularly disposed planes such as before referred tois illustrated in White Patent No. 821,843 of May 29, 1906. It will be obvious that sucha structure is unsuited for use where a flat grille, (that is, one in which it is necessaryto have the 15 bars or strips bounding the interstices in the same the case of refrigerator shelving.

My invention contemplates a method of making cheap flat grilles from work hardening" 1 alloys ormetals such as above referred to; a method of expanding sheets of such metals in the plane of the sheet and not at an'angle to the plane of the sheet as disclosed in said White patent. 5

In the drawings, 1 have illustrated a number of forms of grille structures which can be readily made by my method from sheets of -work hardother metals which are difficult to work because of other characteristics.

Figure 1 schematically depicts the corrugating of a metal sheet forming a step in my method;

Fig. 2 illustrates the sheet after the corrugating step is finished;

Fig. 3 is an edge view of the sheet of Fig. 2;

Fig. 4 depicts the partially expanded sheet;

Fig. 5 is a plan view of a shelf comprising in its make-up a sheet expanded in accordance with this invention;

Fig. 6 is an enlarged view illustrating a corner 0 of the frame structure shown in Fig. 5;

Fig. 7 shows one way of bending up a strip of I metal to form the frame of Figs. 5 and 6.

Fig. 8 illustrates a still further way of forming the frame structure for the shelf of Fig. 5;

Fig. 9 illustrates a metal sheet before corrugating but punched in a manner for producingv a grille in accordance with this invention;

Fig. 10 is an end elevation of the punched sheet shown in Fig. 9 after the same is corrugated; 5 Fig. 11 is a view showing the partially expanded corrugated sheet of Figs. 9 and 10;

Fig. 12 illustrates a portion of a sheet having elongated and shaped slots therein suitable for such as used when making the form of grille shown in Figs. 4, 5, 17, 18, and 19';

Fig. 17 is a schematic view in top plan of a- 15 corrugated sheet andshows by dotted lines an expanded portion of the sheet and part of the mechanism for performing the expanding operation; Y

Fig. 18 is a view in perspective of certain of the 20 tools utilized in carrying out my method and includes part of a corrugated sheet ready to be expanded;

Fig. 19 is an enlarged fragmentary view in per-- spective of a portion of the sheet shown in Fig.

25 18; and

' Fig. 20 is a diagram of my method'of expanding sheet metal in the plane of the sheet without lengthwise stretching of the bounding members of the grille structure.

30 In practicing my method, a metal sheet is provided with corrugations extending in the direction in which the sheet is to be expanded and these corrugations are so positioned that one such corrugation passes through that part of the'sheet 35 from which one series of bars or strips for bounding the interstices are to be sheared.

In all' the forms of grille made in accordance with this invention, I prefer to punch the sheet preferably by means of circular punches to pro- 40 vide round holes which will lie at the junctures of all of the bars or strips bounding the interstices. These round holes located at the junction points of such bars, provide narrowed sections which provide points of bending-.1

.45 In several of the forms, instead of punching circular holesand then slitting, I punch out certain regularly spaced more or less narrow sections,

each having rounded ends; each such section extending the full length of two bounding bars plus o the distance between the adjacent ends of such bars.

Where merely .the circular holes are punched, the sheets are slit between certain pairs of these holes; in such case the sheet is corrugated before 55 the holes are punched. Where; however, in the forms in which narrow elongated sections are punched out, the punching. is done while the sheet is stillflat and the sheet is later corrugated. The corrugations in both cases, however, are regu- 60 larly spaced and are laid out so as to come opposite each series of bars. I

The corrugations in both instances provide the necessary extra length to the bars or, strips in order that the metal may be opened up or ex- ,65 pandedand flattened without stretching the bars or strips lengthwiseo In the opening up operation, which is a step-bystep operation, the metal is merely forced into place by flattening the corrugated parts of the.

70 bounding'bars or strips'into the plane of the flat portion of the sheet.

formed are preferably corrugated with the corrugations running at right angles to the direction 75 in which thesheets are rolled that the sheartion is formed at a time.

Fig. 16 is a schematic view of a shear blade" The sheets from which the grillesare to be ing of the sheets for the expanding operation is with the -ii'rain.

The sheets are preferably corrugated by means of rolls of such a diameter that but one corruga-' For grilles such as I 5 have illustrated in the drawings in which the more or less diamond shaped interstices are approximately 1 x%" rolls of approximately 24" indiameter will permit the forming of one corrugation at a time. In other words,rol1s of this diameter will permit the pulling in of the sheet between'the rolls to provide the necessary stock for each corrugation without overstretching the metal. p

The drawings are all more or less schematic. In Fig. 1 I haveindicatedthe corrugating of a metal sheet in the manner above indicated by corrugating rolls 2| and 22.

Fig. 2 illustrates by full lines the sheet'after the corrugatingstep is finished. The dotted rec-10 tangular portions 23 and 24 represent the amount the sheet is shortened in the corrugating operation.

- Fig. 3 is an edge view of the sheet of Fig. 2 showing the corrugations.

Fig. 4 represents the partially expanded sheet. In this view, I have illustrated the manner of. punching a sheet by circular punchesafter corrugating, to provide circular holes 25. Dotted lines 26 and 21- indicatezthe shear lines or the 30 shearing of the sheet between certain pairsof these circular holes 25. Aj' portion of, the sheet is shown as expanded. i

In this portion, the series of bounding members or strips 28 are in line with corrugations a of the sheet while bounding members 29 are in line with corrugations b.

The corrugationsprovide the necessary extralength to the arms 28 and 29, etc., so that as the sheet is slit and expanded, the bounding members 40 or strips 28, 29, etc., can be moved to their final position in the grille structure without the neces-, sity of stretching the same lengthwise. When the sheet is slit as illustrated, the circular punched holes 25 occasion the formation of rela 5 tively narrow necks 30 which in the expanding operation act as readily bendable sections, that is, sections which are readily bendable in the plane of the sheet. I

It will be seen that when forming the grille illustrated in Fig. 4,.the only scrap metal is that which is punched out by the circular punches.

I find that refrigerator shelves utilizingv grilles such as shown in the expanded partof Fig. 4 can 1 be made from sheet metal such as stainless steel,

Allegheny metal and Monel metal at relatively small cost.

Such a shelf is illustrated in Fig. 5 and is made up of a frame having an outer or bordering por-- tion 3|, an inner support portion 32 having its no upper surface offset below the upper surface of I the outer or borderingportion in an amount equal to the thickness of the grille. The grille member forms the support surface of the shelf and the grille-is preferably spot welded in position on por- 55 tion 32.0f the frame structure.

Fig. 6 is an enlarged view illustrating a corner of the frame structure shown in Fig. 5.

7 shows one way of bending up a strip of suitable metal to form the frame of Figs. 5 and 6.

In this view, the grille is represented by c.

In Fig. 8, I have illustrated another way of .formingup the frame structure from a. strip of suitable metal. 3Ia represents'the bordering 7' portion of the frame and 32a the inner or support portion. The grille is again represented by c.

In Fig. 9, I have illustrated a metal sheet before corrugating, but punched in a manner for the production of the grille structure illustrated in Fig. 11. Instead of slitting the sheet as is done when making the grille structure of Figs. 4 and 5, the punches are .formed so as to punch out from the sheet relatively long narrow sections such as 33. These are staggered with one half sections 34 and full sections 35. Circular holes 36 are also punched in order to carry out the design of grille structure shown in Fig. 11.

Fig. 10 is an end elevation of the punched sheet.

shown in Fig. 9, after the same is corrugated and Fig. 11 is a view showing the partially expanded corrugated sheet of Figs. 9 and 10.

"It will beseen that the corrugations d come in line with bounding members 31 while corrugatione e come in line with bounding members 38. The rounded ends 33a together with the enlargements 33b provide bendable portions 39 which facilitate the opening out or expanding of r the sheet to form the grille structure.

In Fig. 12 I show a portion of a sheet having the elongated and shaped slots 40 punched therein in staggered relation similar to those shown in Fig. 11. In this view, I have indicated by dotted lines at the center line of the corrugations to be formed after the sheet is punched.

Figure 13 is an end view of that portion of the sheet shown in Fig. 12, after corrugating. This view illustrates the foreshortening of the sheet by the corrugating step.

Fig. 14 illustrates the corrugated punched sheet of Figs. 12 and 13 which has been expanded or opened up except for the last two rows of the punched portion.

Since this application is primarily directed to my novel method of making the same, I have not attempted to completely illustrate any organized apparatus or machine for practicing my methodor producing the product in question.

Since a machine for carrying out the method may take numerous forms, I have merely illustrated what might be termed a set of tools which may be used in a machine of any desired construction and which may be used for carrying out the various steps of my method, when properly manipulated and timed. i

In Fig. 15, I have schematically illustrated such a set of tools by means of which my method may be carried out.

Figure 15a constitutes a portion of the set of tools illustrated in Fig. 15, but is a repetition of part of Fig. 15 for the sake of clearness. This view includes an additional element not shown in Fig. 15. g

In Fig. 15, the corrugated sheet of the grille of Figs. 4 and 5 is shown at 4|. This is shown rest- At the back of the ingupon a support table 42. support table, is a pushing device 43 and the mechanism for operating the same will be so constructed that the pusher 43 will move in the direction of arrow 44 in a step-by-step manner so as to feed at each step sheet 4| forward on table 42 a distance corresponding to the width of the bounding bars 28-29 of Fig. 4.

A pusher device 45 located at one side of the table will have an intermittent reciprocatory' movement in an amount equal to one half the length of an interstice; in other words, onehalf of a sheet bounded by bounding members 28 and 29. The opposite side of the support table will be provided with a similar pusher device. The support table 42 has its upper surface grooved with the grooves corresponding to and of the same spacing as the corrugations in sheet 4|.

The corrugations of the sheet depend into the 5 grooves in the support table.

In order that pushing device 45 and its cornpanion may operate to periodically shift the sheet laterally-of the support table and thenback to position, a series of lifting fingers 46 is provided.' If! These are arranged at regularly spaced intervals throughout the extent of the support table 42- and work freely in the vertical bores provided for that purpose in the support table. These pins are provided at their bottoms with disk-like heads 41 '15 and are normally held in depressed position so that their upper ends lie below the support surface of the table. This is accomplished by means of coil springs 48 which surround the pins and lie between the disk-like heads 41 and the and.

48 of enlarged bores 50.

A series of rock shafts 5| having cams 52 is provided for periodically raising pins 46. This is for the purpose of raising sheet 4| so that the corrugations in the sheet will clear the grooves in the table. This allows the sheet to be moved back and forth laterally on the taple. 'Some other means may be utilized if desired for .periodi-'- cally raising the sheet when it is desired to shift the same laterally.

A punch 53 (which represents one of a series extending at spaced intervals across the entire sheet) is provided and carried by a carrier member 54'which is arranged for periodical reciprocation above the support table 42. This punch operates in conjunction with a die block 55 which is let into the support table and which has a circular bore for reception of the series of punches 53.

A carrier member 56 mounted for vertical re- 40 ciprocation alongside of support member 54 carries, adjacent its lower end, a series of stripper a blade holder 60. The blade is preferably 50 formed as shown in Figs. 16 and 18 with portions 6| more or less conforming to the corrugations in the sheet and with a central portion 62 which is bowed downwardly for thepurpose of facilitating shearing and the downward displacement of the sheared portion of the sheet. It will be understood that such a shear blade is used when making grilles such as shown in Figs. 4, 5, 17, 18 and19.

When making grilles such as shown in Figs. 9-14 inclusive no shearing will be necessary and for the upper shear blade a blunt displacer member will be substituted which will merely have the function of moving down below the plane of the sheet supported on the support table 42 the portions which have been segregated from the sheet by the punching of the long narrow portions 34, 35 and 40 (Figs. 9-12 inclusive). The downward displacement of this portion will bein an amount equal to that displaced by shearblades 59 and is merely for the purpose of placing the potential bounding members in position to be enfoot 63 having the major portion of' its under surface smooth and in the plane of the upper surface of the sheet. Below this presser foot which is grooved out as shown by dotted line 54 for a purpose hereinafter to be described is a presser block 55 which is mounted so as tohave an upward movement relative to the plane of the under side of the flattened sheet and a forward movement as indicated by dotted line 55a. The presser block 65 as shown in Fig. 18 is grooved to receive a vertically extending support block 66. The grooves are indicated byvdotted lines 61-68 in Fig. 18. The upper surface of the support block 66 is beveled as shown at 69.-

Extending into each opening 10 of presser block 55 is a horizontally reciprocating 'rod or bar 1| The inner end of this bar is provided with a depending section 12 the under side of which is beveled as shown at 13 to correspond to the bevel 69 formed on the top of block 66. From this it will be seen that as bars II are reciprocated, they will be raised and lowered vertically because of these cooperating beveled surfaces 69 and I3. Each bar H at its forward end is provided with an upstanding hook-like portion 14.

Fig. 16 is a schematic view of a shear .blade such as used when making the form of grille shown in Figs. 4, 5, and 17.

Fig. 17 is a'schematic view and. shows in top -plan and by dotted linesa corrugated sheet in which three rows of circular holes have been punched. Part of the sheet has been expanded and the hooks 14 of the two reciprocating rods or bars H are shown in position ready to open up and form the next row of bounding members;

the partially expanded or opened up sheet is shown by dotted lines in this view.

One roller 15.0f a series forming a roller table is shown beneath the expanded part of sheet 4| in Fig. 15.

. Pusher member 43 is lined up so as to abut against the rear edge of sheet 4|. Side pusher 45 is lined up so as to abut against its side ofsheet 4|. The" v forward edge of sheet 4| will extend beyond the row of punches 53 an amount equal to thewidth ;of the bounding bars 28 and 29 (Figs. 4 and 5).

It will be seen that the series of tools above described comprises a sheet support table, means for raising the sheet from the table so that the same may be reciprocated back and forth laterially; a pusher for advancing the sheet one step at a time, a series of punches forming a gang punch; a series of strippers straddling the punches'of the gang and extending across above the sheet from side to side; a hold down'bar arranged to clamp the sheet in position on the lower stationary knife blade; a shear knife which is reciprocated to shear the sheet and move the sheared portion down a distance below the plane of the sheet; a presser foot and a presser block for flattening out the corrugations of the severed portions and puller bars for opening up or expanding sheared of! portions of the sheet.

These several tools will be timed so that after a certain number'of lines of holes have been "punched-say three lines (the: pushers 43 and 45 having been operated in the meantime to,

- properly position the sheet for punching) and the sheet reaches the position to be sheared it will be clamped in position between clamp bar and stationary knife blade 58. As the upper.

blades are retracted after the first shearing operation, hold down bar 56 is raised and .the pusher member 43 advances the sheet the proper distance-for the next'shearing operation. Kick up pins 46 are then operated to raise the sheet 7 clear of the grooves of the. table 42, and side pusher member 45 moves the sheet sidewise for the next punching and shearing operation. The forward and sidewise movement of the sheet occasioned by means of pushers 43 and 45 so positions the sheet that the sheared of! portions which now lie below the. normal plane of the sheet-as shown in Figs. 18 and i9 lie in front of hooks 14 of puller bars 1|.

The hold down bar next descends and clamps 5 the sheet between the lower stationary knife blade 58 and the bottom of the hold down bar. The gang punch descends and punches a new series of holes and the pull out bars H immediately operate to expand the cut of! portions of 51.

Simultaneously with the expanding movement, 30

of puller bars 1|, presser block rises and moves forward to flatten out the corrugations "in the sheared off portions of the sheet or in other words in the potential bounding members.

Presser foot 63 while it is substantially flat on 35 its under surface except for groove 54, preferably has a slight curvature from its forward to its rear end. This bar will be suspended on about a 20 radius so that it can swing forward as presser block 55 moves forward and upward to flatten out the portions of the sheet lying therebetween.

After the opening up or expanding and flattening operations of the severed portions have been accomplished, the presser block 85 recedes to nor- 4 ma] position, that is, it moves angularly downward; pull out bars 1| return to normal position against the stationary knife blades 53: the gang -punch is raised and hold down bar 55 is raised and pusher 43 advances the sheet'one step; the 50 kick out pins then raise the sheet free from the table and the proper side pusher then moves the sheet laterally the desired distance for the next cycle of operation.

In Fig. 20 1 have attempted to schematically 55 show my method of expanding'sheet metal in the plane of .the sheet without lengthwise stretching of the bounding members of the grille structure. I have assumed thatI am forminga grille struc-' ture having more or lessdiamond shaped inter- 6o stices which are 2%.? long x 1H" wide. It will be seen that when the expansion takes place to, open up the metal iii of an inch wide each arm. forming the diamond boundary has a length of 15" while the same length is maintained in the diamond as was the length sheared oi 2%";

Therefore, the metal provided by corrugating the sheet has furnished additional metal which allows forming the diamond in the opening-up process without stretching the metal the "m i A" increased length as shown.-

Having thus -described my invention, what I claim as new and desire to secure by Letters Patentis:--

1. In the method of making an expanded metal grille in which the 'suriaces 'ot the bars bounding its interstices lie in a-common plane,

' the steps consisting in forming corrugations in a metal sheet or strip which corrugations extend l in the direction in which the material is to be expanded, in slitting the material atspaced positions with the slits extending at right angles ,to

the corrugations andthen in expanding or pulling out the slit portions. of the material and 10 during such pulling out 'procedurein flattening the corrugated partsot such slit ofi portions into "the plane of the original stripor sheet.

2.- In the method 01' making an expanded metal grille, the steps consisting informing corrugaifl tions in a metal sheet-like member and extending in the direction in which'the material is to be expanded, in punching a series of spaced holes in sheet metal blank having staggered portions which are severed from the blank except at their ends and center and corrugations which extend in the direction in which the expansion is to occur 80 and at right angles to the major axes of such severed portions, the steps whichconsist in progressively expanding the corrugated blank and simultaneously with such expanding procedure in flattening the corrugated parts 01- the expand- 85 ed severed portions so that the completeh'r-ex panded is flat and the upper surfaces. oi all 'ot its parts lying in one; common plane.

. 4. In making an expanded metal grille from a 1 sheet metal blank having. staggered portions 5- which'are severed from the blank except-attheir ends and center and corrugations which extend in the direction ln'yvhich the expansion is to occur and at right anglesto the major axes of such severed portions, the steps consisting in ex'pand- 10 ing one row oi. such severed portions at a time and simultaneously with such expanding procedure in flattening the corrugated parts of such severed portions so that the expanded part is hat and with the upper surfaces of allits parts 15 lying in one common plane; such plane being the plane or the uncorrugated parts of the blank. 5. In a method of making an vexparfded metal grille having regularly spaced interstices and with the upper surfaces of the membersbounding 20 such interstices lying in a common plane, thesteps which consist in punching from a sheet metal blank regularly spaced portions to form a fiat reticulated structure, in corrugatin'g such structure with the corrugations intercepting the g5 vbounding members of the .reticulations and then in expanding the reticulated blank in the direction in which the corrugations extend and simultaneously with such expanding procedure, in flattening the corrugated portions whereby an .exso -panded metal blank is. formed in which the bounding members for the interstices'are all flat and withtheir upper suriacesin one common plane.

' QTHOM. O'Il'I'll. I 

